Shear wave velocity estimation based on the particle swarm optimization method of HVSR curve inversion in Bakauheni district, Indonesia

Abstract

The Nakamura method, known as horizontal to vertical spectral ratio (HVSR), has been used to analyze site effect assessment. Over the past decade, various HVSR curve inversion methods for near-surface geophysical surveys have been developed. Particle swarm optimization (PSO) inversion method has been applied to solve the HVSR inversion curve to estimate the shear wave velocity (Vs) value towards the depth. In this study, the HVSR curve inversion experiment has been applied with two synthetic data: noise-free data and the other is contaminated by 10% random noise. This research aims to find out how the PSO algorithm performs to find the best solution. The result indicated that the PSO algorithm is relatively stable fast in converging and producing the solution closely with the actual model. Finally, we obtained a fit model on actual data inversion that shows the Vs value towards depth from PSO inversion and is able to describe the fault model and sediment layer in Way Baka fault.